Abstract

Urinary tract infections (UTIs) are common, and over half of women report having had at least one in their lifetime. Nearly a third of these women experience recurrent UTI episodes, but the mechanisms of these recurrences are not fully elucidated. Frequent use of antimicrobials for treatment and prevention of UTIs and other infections has contributed to the evolution of multidrug-resistant microorganisms globally. This is a looming worldwide crisis that has created an urgent need for novel strategies for the treatment and prevention of UTIs. Furthering our understanding of the mechanisms of recurrent UTIs, from both host and bacterial perspectives, will be paramount in developing targeted management strategies. In this review, we discuss recent findings regarding recurrent UTIs in women, including progress in our understanding of the mechanisms of recurrence as well as emerging treatments.

Possible modes of UTI recurrence. Recurrent UTIs can be introduced from a number of sources. 1. The same UTI-causing strain (green bacteria) persists in the gut and repeatedly re-inoculates the bladder. 2. A different strain (red bacteria) is introduced first into the gut and then colonizes the bladder. 3. Quiescent bacteria reside in the bladder epithelium and re-emerge periodically to cause same-strain UTI (green bacteria). 4. A new strain of bacteria is introduced directly into the peritoneal area from the environment (blue bacteria).